Messages in this thread | | | Date | Thu, 16 Aug 2018 15:21:17 +0100 | From | Quentin Perret <> | Subject | Re: [PATCH v3 03/14] sched/core: uclamp: add CPU's clamp groups accounting |
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On Thursday 16 Aug 2018 at 15:45:45 (+0200), Dietmar Eggemann wrote: > On 08/16/2018 03:37 PM, Quentin Perret wrote: > > > > IMHO, if this is something which should not happen at all, a BUG_ON() is the > > > > right thing to do here. > > > > > > I don't agree on that. I agree it should not happen but since it's a > > > recoverable error it think we should not panic. > > > > FWIW, if this is a recoverable error, I think Linus will agree with > > Patrick on this one :-) > > > > https://lkml.org/lkml/2016/10/4/1 > > Yeah, not really agreeing here that this is a recoverable error.
A non-recoverable scenario could be, for example, if you corrupt your stack and there is absolutely _nothing_ you can do to keep the system up and running, because it's just too broken. I don't feel like we're talking about such an extreme case here ...
> Besides, we > only consider under-run here, what about over-run? > > Currently this warning doesn't hit and if the code will be changed and it > hits, I still find a BUG_ON more appealing here ... > > So this error scenario can happen over and over again and we always recover > from ? The important thing is that we find the culprit for this behaviour as > fast as possible ...
Agreed, we want to debug that ASAP, but WARN should let us do that just fine, I think.
Quentin
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